Playing Dungeons and Dragons is a threat to prison security, a court has ruled - because it encourages prisoners to cooperate.

A three-judge panel of the United States Court of Appeals for the Seventh Circuit this week concluded that "cooperative games can mimic the organization of gangs and lead to the actual development thereof."

...

The judges conceded that there was no evidence that playing D&D had ever led to a single incident of violence. However, they still sided with the prison.

Their conclusion was, in effect, that it didn't matter whether or not D&D really led to gang activity - only whether prison officials were reasonable in thinking it might. And they pointed out that inmates could always play something else instead (Snakes and Ladders? Barbie and the 12 Princesses?). Singer's appeal was denied.